Bath for containing and receiving a plurality of aperture tubes

ABSTRACT

A BATH HAVING A POCKET PORTION FOR RETAINING TESTTUBELIKE APERTURE TUBES KNOWN IN THE ELECTRONIC PARTICLE ANALYSIS ART. THE BATH HAS A DEPENDING, ELONGATED, FLUID PASSAGE BORE, PREFERABLY DEFINED BY SIDE WALLS TRACING A SEGMENT OF AN EXPONENTIAL CURVED. FLUID ENTRANCE AND EXIT LINES ENTER THE PASSAGE BORE NEAR ITS BOTTOM, SUCH THAT FLUID FLOW UPWARD INTO THE POCKET CHAMBER IS SMOOTH AND WITHOUT SIGNIFICANT TURBULENCE, SQUIRTING, OR BUBBLING THE BATH, ASSOCIATED APERTURE TUBES, ELECTRONIC AND OPTICAL DETECTING ELEMENTS PROVIDE AN IMPROVED COMBINATION USEFUL IN PARTICLE ANALYSIS.

March" 2 1971' w. R. HOGG 'BAm FOR cormmme AND RECEIVING A PLURALITY OF'APERTURE TUBES Filed July 22, 1968 wow INVENTOR WALTER R. HOGG mom ATTYS.

United States Patent O 3,567,321 BATH FOR CONTAINING AND RECEIVING A PLURALITY F APERTURE TUBES Walter R. Hogg, Hialeah, Fla., assignor t0 Coulter Electronics, Inc., Hialeah, Fla. Filed July 22, 1968, Ser. No. 747,782 Int. Cl. G01n 21/26, 27/42 US. Cl. 35672 10 Claims ABSTRACT OF THE DISCLOSURE A bath having a pocket portion for retaining testtubelike aperture tubes known in the electronic particle analysis art. The bath has a depending, elongated, fluid passage bore, preferably defined by side walls tracing a segment of an exponential curve. Fluid entrance and exit lines enter the passage bore near its bottom, such that fluid flow upward into the pocket chamber is smooth and without significant turbulence, squirting, or bubbling The bath, associated aperture tubes, electronic and optical detecting elements provide an improved combination useful in particle analysis.

FIELD OF THE INVENTION The invention concerns fluid handling devices useful in biological and industrial processing of small samples in sequential batches and, more particularly, to an improved bath designed to accommodate a plurality of aperture tubes commonly associated with particle analysis equipment sold under the registered trademark Coulter Counter.

DESCRIPTION OF THE PRIOR ART Art pertinent to this invention would be commonly associated with inventions and products owned and produced by Coulter Electronics, Inc., Hialeah, Florida, the assignee of this invention. United States Pat. 2,656,508 discloses basic apparatus for electronically accomplishing particle analysis through use of the scanning ambit of a tube having a microscopic aperture, i.e., an aperture tube. Numerous patents and application are directed to improved structures, systems and methods for utilizing aperture tube particle analysis. Copending United States applications Ser. No. 509,986, filed Nov. 26, 1965, Pat. No. 3,444,464 and Ser. No. 527,146, filed Feb. 14, 1966, disclosed electric apparatus, method, and structure for simultaneously employing a plurality of aperture tubes for improved particle analysis. Copending United States application Ser. No. 631,284, filed Apr. 17, 1967 is directed to a comprehensive, automated system for blood analysis, such system employing a pair of aperture tube baths, each retaining a plurality of aperture tubes. The present invention is directed to an improved aperture bath and its immediately associated system elements.

The aperture bath of the prior system application is a small glass pocket having a large open mouth at its top and contains a fluid sample input port near its mouth. A pair of fluid ports are coupled to the bottom of the pocket by a short cylindrical stem portion. These latter .ports enable draining as well as an upwardly directed rinsing of the bath at least once each analysis cycle. Although this bath operates satisfactorily, it does exhibit certain somewhat undesirable characteristics. The incoming tangential and downwardly directed sample tends to spray and squirt into the chamber of the pocket if pressure, and other flow parameters are not properly controlled. Such results in lack of economic use of the micro samples, greater difficulty in rinsing the bath clean, etc. The upwardly directed rinse solutions also have a tendency ice to squirt and bubble; thus, lessening the efliciency of the cleansing process, lengthening such process by causing it to be repeated, and requiring more rinse solution. Yet also, the draining of sample and rinse solution lack fluid 5 smoothness; hence, a uniformly, optimally clean bath for each subsequent sample is difficult to achieve. Accordingly, the precision of the particle analysis could suffer to a slight degree.

BRIEF SUMMARY OF THE INVENTION The invention overcomes the limitations of the prior art bath and combined elements by providing an improved bath of pocket configuration having all fluid ports positioned near the bottom of the bath and well below the chamber of the pocket. Joining the ports to one another and to the chamber is an elongated, generally vertical bore of regular cross section, preferably defined by a side wall which traces a segment of a catenary curve, with its larger mouth end smoothly opening into the pocket chamber.

Accordingly, it is a primary object of this invention to provide an improved bath in which fluid is transmitted smoothly via an elongate, tapered bore into the main chamber of the bath.

Another object of the invention is to provide an improved bath for a plurality of aperture tubes in which all fluid ports are disposed below the apertures and are spaced therefrom by an elongate bore of regularly changing cross section having its end closer to the apertures of larger periphery than the end closer to the ports.

A further object of the invention is to provide a bath having its fluid chamber separated from its depending ports by a bore defined by a side wall which traces a segment of a curve of an exponential character, such that the cross sectional area of the bore increases gradually.

Yet another object of the invention to provide the combination of a plurality of aperture tubes and an aperture tube bath in which fluid flows smoothly, both upwardly into the bath and downwardly therefrom.

A further object of the invention is the improved combination of particle detecting elements, aperture tubes and an aperture tube bath in which a minimum of sample and rinse solutions is employed to maximum efficiency with optimal results because of improved fluid flow characteristics of the combination.

The above objects and further objects and advantages will become apparent from the next following disclosure of a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the inventive bath in combination with the white cell sample aperture tubes and detecting elements, with diagrammatic representation of hemoglobin measuring apparatus.

FIG. 2 is a view, substantially in section, taken generally on the line 2-2 of FIG. 1 and in the indicated direction.

FIG. 3 is a magnified, fragmentary sectional detail of FIG. 2 taken generally in a vertical plane on the line 33.

DESCRIPTION OF THE PREFERRED EMBODIMENT At the outset, it would be convenient to outline the general scheme of the system disclosed in the copending system application Ser. No. 631,284 by explaining the functions which are performed in the fluid handling portions of the complete system.

The blood sample is taken in any convenient manner and in whole form is identified by a suitable marking, usually in the form of a card having blanks upon which the desired information will be printed by the printer of the apparatus. The apparatus has a tube or snorkle which is dipped into the sample and draws a quantity into the fluid system. A minute measured part of this Whole blood is transferred into a first mixing chamber along with a predetermined quantity of diluent Where the first dilution occurs. From this first chamber a first portion of the first dilution goes to a second mixing chamber along with an injected lysing agent and hemoglobin reagent, where the first portion is permitted to remain for a time suflicient to enable the red blood cells to be broken up to release their hemoglobin. Also, from the first mixing chamber a second portion is withdrawn and further diluted in a third mixing chamber to provide the red blood sample.

Each of the resulting samples is handled separately after once having been made. The sample containing only the free hemoglobin and white cells is passed into a bath, an improved version of which is a subject of the present disclosure, where there are three aperture tubes, and is sucked into all three tubes simultaneously with a constant fluid pressure for a predetermined period of time. The aperture tubes are provided with respective electrodes and there is a common electrode in the bath, so that three sets of signals are obtained by virtue of the passage of the white cells into the aperture tubes. Electronic circuitry provides an output from a detector which represents white blood cell count directly. The white cell sample, having the hemoglobin, enables the hemoglobin determination to be made in its aperture tube bath. Accordingly, this bath provides parallel viewing faces through which a beam of suitable light can be passed through the suspension and into a photo-responsive device to give information concerning the hemoglobin parameter of the original sample. Suitable electronic circuitry connected with the output of the photo-responsive device gives a quantity which represents hemoglobin.

The red blood suspension in the meantime has been passed into a similar bath having aperture tubes, electrodes and electronics to detect the signals resulting from the scanning of the suspension as it passes into the aperture tubes. A similar vacuum system or pump provides constant pressure and, as in the case of the white cell arrangement, the scanning occurs for a predetermined length of time representing a flow of a given volume of liquid into all three aperture tubes.

The apparatus has means for filling and emptying the various vessels, as well as for discharging waste comprising excess liquids. Once started, the operations are continuous and the respective samples do not contaminate one another.

For ease of comparative study with the copending system application, the reference numerals employed with respect to its FIGS. 35 will be employed in this disclosure to the extent practical.

With reference to FIGS. 1 and 2, the bath 90 is preferably a glass jar or pocket open at the top as shown at 2-10 and narrow in its bottom portion as shown at 212. A chamber 214 formed on the interior of the bath is rather narrow, especially within the portion 212, and aperture tubes 144 which are disposed in the chamber are flattened so that a minimum of sample will rise quite high in the chamber 214. For example, a level is shown at 216 in FIG. 2 above the apertures 146. These aperture tubes are set into a plate 218 by means of which all three of the aperture tubes may be raised or lowered at the same time. This plate is engaged in a large carrier (not shown) which overlies the upper end of the bath 90. The top ends of the aperture tubes are fitted with caps 219 which are adapted to be coupled to fiuid sample withdrawing means (not shown) via lines 198.

Near its bottom end, the bath is formed with faces 220 and 222 which are paraiiel and flat. A light source, projector, filter etc. 202, 204 of standard specifications directs a beam 224 to a hemoglobin determining device 206 via the same suspension that 'is being used for achieving the white cell counts. The sample is introduced from a line 120 into a spud or port 226, the bore 228 of which is normal to a specially designed conduit portion 4, having an elongate bore 5, preferably of circular cross section, and an outwardly curving profile which is defined, in a preferred embodiment, by an interior wall 6 which traces a small segment of an exponential curve, which causes the cross-sectional area of the bore to increase gradually. Although other curves will operate satisfactorily, and the cross section may be other than circular, such as elliptical, an exponential profile has been found to provide excellent, smooth fluid flow results.

At the bottom of the bore 5 is a cross conduit 7 coupling a pair of ports or spuds 8 and 9 to the bore 5. The spuds 8 and 9' are to be coupled to fluid lines 138 and 1.35, respectively, to facilitate the rinsing and flushing of the bath. The relationship of these elements is shown in greatly magnified section in FIG. 3, which clearly illustrates the smooth contour of the bore 5 from the cross conduit 7 to the juncture of the bore with the chamber 214. The continuously increasing cross section of the bore 5 elfects a smooth, nonturbulent fluid flow from the spuds 8 and 226: through the bore 5 and into the chamber 214. Depending upon the rate of fluid flow, fluid pressure, fluid viscosity and the cross-sectional diameters of the portions 5, 7, and 228, the length and configuration of the bore 5 may require slight modification for optimal results. Under the least taxing of conditions, the bore 5 can be effective if only simply tapered, such as a cone. 7

Accordingly, the simplest configuration of the bore 5 is one that has a large end or mouth contiguous with the bottom of the chamber 214; a first peripheral dimension with a substantially smooth, regular shape, such as a circle or ellipse; a remote second end opening into the cross conduit "7; and a second peripheral dimension smaller than the first peripheral dimension with a regular, smooth shape which may or may not be the shape of the first periphery. The shape of the bore between the two ends is smooth and substantially regular to maximize the smoothness of fluid flow within the bore 5 and into the chamber 214. The increase of cross-sectional area in the direction toward the chamber 214 uniformly reduces the rate of fluid flow in that direction to minimize squirting and surface turbulence.

Returning to FIGS. 1 and 2, each aperture tube 144 has its own interior electrode 230 with a conductor 231 leading to a detector (not shown). A common grounded electrode 232, having a lead 233, is disposed in the chamber 214 so that as particles pass through the apertures they will produce signals across the electrodes and across the electric leads 231 and 233 connected to said electrodes for counting, sizing, etc. Each of the three apertures is illuminated by a source of light 234 which generates a beam 238, there being some form of condensing lens 236 used to focus the beam 238. Each beam 238 passes through its respective aperture, which is usually quite close to the side 'wall 222, and is then directed upon a mirror 239, from which the aperture ap pearance may be projected onto a ground glass screen. in this way all three apertures and their state of o erabil- 1ty may be viewed optically simultaneously. r

Assuming the bath and the aperture tubes 144 to be empty and clean, the combination or" elements would be operated and utilized sequentially as follows. A metered amount of fluid sample would be introduced into the l1ne and, via the spud 226 and its bore 228, would flow smoothly into the bore 5 and up into the chamber 214 until the apertures 146 were immersed. The sample would not flow from the cross conduit 7, because valves 1n the lines and 138 would be closed. Because of the configuration of the bore 5, the incoming sample would have little or no tendency to squirt or bubble up and into the chamber 214.

Parameters of the sample would next be measured by the described electronic and optic structures, while a very small portion of the sample was being drawn into the aperture tubes 144 via the aperture 146. Next, the line 138 would be opened and the bath drained of sample. Thereafter, the line 135 would be opened to a supply of rinse solution which, while the lines 120 and 138 were closed, would enter into the bore and chamber 214 and rinse same. Again, the contour of the bore 5 would facilitate the desired fluid flow characteristics to insure a resultingly clean bath structure. Finally, the line 138 would be reopened and the rinse solution drained so as to enable the bath to next receive its next sample. If required, repeated rinses can be provided from one or more sources via one or more lines, such as 135.

Thus, the bath 90 per se as well as the improved combination of elements is highly suited to accomplish the initially set forth objects. In addition to the suggested variations to the preferred embodiment, particular environmental considerations may lead to modifications which are contemplated to be within the spirit and scop of this invention.

What is sought to be secured by Letters Patent of the United States is:

1. Apparatus suitable for fluid sample analysis comprising:

a bath having a pocket portion defining a fluid chamber having an upper end and a lower end, said upper end being open to the atmosphere,

an elongate bore depending from said lower end, and

a port portion secured to said bore at a position remote from said chamber lower end,

said bore having a cross section adjacent said chamber lower end similar to that of the lower end and significantly greater than its cross section adjacent said port portion, and defining a primary and direct path for fluid flow into and from said fluid chamber,

the relations of said chamber, bore and port portion being such that fluid flow to and from said chamber via said bore and port portion is smooth and substantially free of squirting and disruptive bubbling.

2. Apparatus suitable for fluid sample analysis and for housing a plurality of particle analyzing aperture tubes comprising:

a bath having a chamber with an open mouthed upper end for receiving the aperture tubes,

a substantially closed and narrowed lower end proximate the position of the apertures of the aperture tubes,

a bore projecting from said lower end,

fluid port means coupled to said bore at a position significantly remote from said lower end and adapted to receive at least two fluids and provide a drain for said bath,

said bore having a configuration which promotes the smooth flow of fluids into said pocket at a rate significantly and gradually diminished from that at the port portion.

3. Apparatus suitable for fluid sample analysis comprising:

a bath defining a fluid retaining and flow through chamber,

at least one particle analysis aperture tube,

said bath and said aperture tube configurated such that the aperture tube is mounted for ready removal from the upper end of said bath and is generally dependent therein with its aperture disposed such that a minimal amount of fluid sample entering the chamber from below the level of the aperture will immerse the aperture, an elongate bore of smooth axial configuration dis posed in said bath in depending relation at a point below the level of the aperture of the aperture tube, and a port portion secured to said bore axially remote from said aperture tube for exclusive delivery of any fluid sample, the diameter of the bore proximate the port portion being significantly less than at its end proximate the aperture tube. 4. Apparatus as defined in any one of claims 1 through 3 in which said bore has a regularly changing cross section and is defined by a side wall which has a curved profile throughout most of its length from said port portion to said chamber lower end. 5. Apparatus as defined in any one of claims 1 through 3 in which said bore is defined by a isde wall which traces a segment of a curve of exponential character throughout its length. 6. Apparatus as defined in any one of claims 1 through 3 in which said port portion provides the only fluid communication with said bore and chamber, and the length of the bore is significantly greater than its average diameter so as to be tapered throughout its length. 7. Apparatus as defined in any one of claims 1 through 3 in which said bore is of circular cross section and has a side wall which traces a segment of a mathematically prescribed curve. 8. Apparatus as defined in any one of claims 2 or 3 in which said bore is significantly elongate, and said apparatus further comprises electro-optical means positioned external said bath for accomplishing fluid sample analysis of fluid sample in the bath at a position removed from said bore, port portion and aperture tube, said bath having generally flat and parallel side walls for alignment with said electro-optical means. 9. Apparatus as defined in any one of claims 1 through 3 which further comprises electrode means for enabling the passage of an electric current through the fluid sample, said electrode means disposed within said chamber at a position appropriate for immersion by said fluid sample by the flow of sample from said bore into said chamber. 10. Apparatus as defined in any one of claims 1 through 3 in which said bore has a cross-sectional area which gradually increases throughout its length.

References Cited UNITED STATES PATENTS 3,020,795 2/1962 McKinney et al 356-246 RONALD L. WIBERT, Primary Examiner O. B. CHEW II, Assistant Examiner US. 01. X.R. 250218; 324 71; 356--208, 246 

